Cobratac flip up sight troubles

I bought a pair and have been trying to zero. Currently I only have access to a 75 foot range.

I have tried to zero multiple times with these sights. Grouping is great, but I’m high no mater what. Instead of aiming center mass, I have to drop down about 2-3 inches to hit center mass…

I have tried going up and down.

I have a low pro gas block on free float, should I need to use a riser?

All help is appreciated!

Well, apparently they are out of spec but I sent them back for replacement. I will keep everyone informed.

Any info on this yet?

Yes. Sorry. So the manufacturer sent me a new set and told me the old ones were somehow out of spec. The new ones were the upgraded “pro” version. They zeroed with no issue but I ended up buying a set of Magpul MBUS gen 2 sights just because I lost all faith in these sights. Sometimes you get what you pay for.